Dental instrument.



PATENTED MAR. 24, 1908.

W. B. PEARSALL. DENTAL INSTRUMENT. APPLICATION FILED we. a. 1906.

UNITED STATES PATENT OFFICE.

DENTAL INSTRUMENT.

Specification of Letters Patent.

Patented March 24, 1908;

Application filed August 6, 1906. Serial No. 329,457.

To all whom it may concern:

Be it known that I, WILLIAM BOOTH PEARSALL, a subject of the King of Great Britain and Ireland, residing at Merrion, 97 Finchley road, borough of I-Iampstead, county of London, England, have invented certain new and useful Improvements in Instruments for Dentists Use; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention for an improved instrument for dentists use relates to an instrument for pressing gold, platinum or alloy foils into cavities of teeth or casts made from such cavities from which to make matrices in which porcelain for repairing the natural teeth by inlay is afterwards baked. These instruments are also intended for use in making plates for dentures with thin sheetmetal or casts of the mouth made of impression material, plaster of paris, Spence metal, fusible metal, or other alloys cast in facsimile of the parts of the mouth to be fitted. The instruments will also be found useful for pressing amalgam fillings into cavities of the natural teeth, thus compelling this filling material to adapt itself to the walls by rolling without the disturbance that takes place in the bedding of this material in the cavity by the usual method. When large cavities have to be filled or large portions of the crown of a tooth have to be restored their contours can be quickly rolled or modeled to a suitable shape so that the cusps of the opposing teeth of the other j aw can be fitted.

According to this invention, the instrument consists of a stem or handle adapted to be held in the hand and inserted in the mouth, and a revolving head or roller mount ed to revolve on the end of the stem and I of the rollerbeing either toothed, milled, or smooth, to suit different work. With the aid of this instrumentfoil one-thousandth of an inch in thickness can be accurately filled into the cavity and caused to conform to the contour thereof without creasing or folding.

In the accompanying drawing Figures 1 and 2 are side views of dental instruments constructed according to this invention. Fig. 3 is an enlarged section taken through the head of the instrument shown in Fig. 1, showing one method of mounting the revolving head; and Fig. 4 is an enlarged section of the head shown in Fig. 2.

The instrument consists of the handle or stem at and the head I) which is mounted coaXially with and adapted to revolve on the bent end of the stem. Instruments with revolving heads of various shapes and sizes may be used according to the work to be done. As shown in Figs. 1 and 3, the instrument has a pear-shaped head, while that shown in Figs. 2 and 4 is substantially cylindrical. In attaching the head or roller b to the stem at the end a of the stem is reduced in diameter, a shoulder d being formed for the head I) to abut against. The end 0 may pass either partly or entirely through the head I). As shown in Figs. 3 and 4 the reduced end 0 passes through the revolving head and is expanded at f to retain the head in position, the head being formed with a countersunk or similar recess e, which is closed by the riveted head f.

What Iolaim and desire to secure by Letters Patent is A dental instrument of the character described consisting of a stem or handle having a bent end 0, the latter being reduced in diameter and having a shoulder d, a head rotatably mounted on the end 0 and abutting against the said shoulder, and an expanded head on the end 0 to hold the rotatable head in position on said end. I

In testimony whereof I have afiixed my signature, in presence of two witnesses.

WVILLIAM BOOTH PEARSALL.

Witnesses:

H. D. JAMESON, F. L. RAND. 

